Change HistoryDiscussion of Boxsters and other Porsches |  |  |
|
Buying through this link, gets PB a donation. |
Products for your Boxster, Cayman and Carrera. |
 | |
Message: Based on the rareness of head gasket failures I'd have to question the head gasket diagnosis...
Changed By: MarcW
Change Date: July 17, 2014 02:06PM
Based on the rareness of head gasket failures I'd have to question the head gasket diagnosis...
Change Date: July 17, 2014 02:06PM
Based on the rareness of head gasket failures I'd have to question the head gasket diagnosis...
More common it seems is a head is cracked.
I wonder upon what basis the gasket diagnosis was made?
Anyhow, an engine sipping coolant does not have to be anything more sinister than a bad coolant cap.
The car does not have enough miles really to suspect the plugs, though if they are original they may be due to be replaced on time rather than mileage. Also, the misfiring is too spread out to likely be from a head gasket problem.
However, when replacing the plugs the tech can probably confirm one way or the other the head gasket theory, from the appearance of the plugs. A cylinder with coolant will produce a rather clean plug.
Absent clear signs there is a head gasket leak, with the history of the car, its lack of use, I'd be more likely to suspect mice damage to the wiring, hoses, maybe even a coolant hose. I've seen a hole chewed into a gasoline vapor line -- the creature probably stopped when it got a snoot full of gas vapor -- so there's no reason to believe the same couldn't happen to a coolant hose.
Before you decide what to do you need to know exactly what is wrong. Then you can make a better decision.
Let's say the head gasket is bad. You need to price a fix. Now you have to be careful. A long term coolant leak can compromise the head (or block) surfaces and a new gasket might not hold. The "fix" is to take a skim cut across the block and head to restore these surfaces to the flatness/surface finish that a head gasket requires to do its job. The skim cut may not be doable as the damage to the head or block is too severe. If the block needs doing the comes out of the car -- it may have to come out anyhow to get at the head -- and would need to be disassembled so the block could be machined, cleaned up, then put back together again. You want to be sure you have the right shop tackle this job. You can spend a lot of money having the block and head machined if they do not need it. But you can spend a lot of money doing the head gasket repair again on top of then having the block or head machined to ensure this time the head gasket holds.
You'll have to work the numbers to see what the damage is if you decide to fix the car vs. unload the car. As it sits with a suspected (and "diagnosed") head gasket problem, combined with misfiring, and what have you the car is not worth much. Thus you take a bit hit in depreciation. Of course you also know what you have lost. You are done with the car and can move on.Let's say the head gasket is bad. You need to price a fix. Now you have to be careful. A long term coolant leak can compromise the head (or block) surfaces and a new gasket might not hold. The "fix" is to take a skim cut across the block and head to restore these surfaces to the flatness/surface finish that a head gasket requires to do its job. The skim cut may not be doable as the damage to the head or block is too severe. If the block needs doing the engine comes out of the car -- it may have to come out anyhow to get at the head -- and would need to be disassembled so the block could be machined, cleaned up, then put back together again. You want to be sure you have the right shop tackle this job. You can spend a lot of money having the block and head machined if they do not need it. But you can spend a lot of money doing the head gasket repair again on top of then having the block or head machined to ensure this time the head gasket holds.
You'll have to work the numbers to see what the damage is if you decide to fix the car vs. unload the car. As it sits with a suspected ( and "diagnosed" ) head gasket problem, combined with misfiring, and what have you the car is not worth much. Thus you take a bit hit in depreciation. Of course you also know what you have lost. You are done with the car and can move on.
I wonder upon what basis the gasket diagnosis was made?
Anyhow, an engine sipping coolant does not have to be anything more sinister than a bad coolant cap.
The car does not have enough miles really to suspect the plugs, though if they are original they may be due to be replaced on time rather than mileage. Also, the misfiring is too spread out to likely be from a head gasket problem.
However, when replacing the plugs the tech can probably confirm one way or the other the head gasket theory, from the appearance of the plugs. A cylinder with coolant will produce a rather clean plug.
Absent clear signs there is a head gasket leak, with the history of the car, its lack of use, I'd be more likely to suspect mice damage to the wiring, hoses, maybe even a coolant hose. I've seen a hole chewed into a gasoline vapor line -- the creature probably stopped when it got a snoot full of gas vapor -- so there's no reason to believe the same couldn't happen to a coolant hose.
Before you decide what to do you need to know exactly what is wrong. Then you can make a better decision.
Let's say the head gasket is bad. You need to price a fix. Now you have to be careful. A long term coolant leak can compromise the head (or block) surfaces and a new gasket might not hold. The "fix" is to take a skim cut across the block and head to restore these surfaces to the flatness/surface finish that a head gasket requires to do its job. The skim cut may not be doable as the damage to the head or block is too severe. If the block needs doing the comes out of the car -- it may have to come out anyhow to get at the head -- and would need to be disassembled so the block could be machined, cleaned up, then put back together again. You want to be sure you have the right shop tackle this job. You can spend a lot of money having the block and head machined if they do not need it. But you can spend a lot of money doing the head gasket repair again on top of then having the block or head machined to ensure this time the head gasket holds.
You'll have to work the numbers to see what the damage is if you decide to fix the car vs. unload the car. As it sits with a suspected (and "diagnosed") head gasket problem, combined with misfiring, and what have you the car is not worth much. Thus you take a bit hit in depreciation. Of course you also know what you have lost. You are done with the car and can move on.Let's say the head gasket is bad. You need to price a fix. Now you have to be careful. A long term coolant leak can compromise the head (or block) surfaces and a new gasket might not hold. The "fix" is to take a skim cut across the block and head to restore these surfaces to the flatness/surface finish that a head gasket requires to do its job. The skim cut may not be doable as the damage to the head or block is too severe. If the block needs doing the engine comes out of the car -- it may have to come out anyhow to get at the head -- and would need to be disassembled so the block could be machined, cleaned up, then put back together again. You want to be sure you have the right shop tackle this job. You can spend a lot of money having the block and head machined if they do not need it. But you can spend a lot of money doing the head gasket repair again on top of then having the block or head machined to ensure this time the head gasket holds.
You'll have to work the numbers to see what the damage is if you decide to fix the car vs. unload the car. As it sits with a suspected ( and "diagnosed" ) head gasket problem, combined with misfiring, and what have you the car is not worth much. Thus you take a bit hit in depreciation. Of course you also know what you have lost. You are done with the car and can move on.
Original Message
Author: MarcWDate: July 17, 2014 02:03PM
Based on the rareness of head gasket failures I'd have to question the head gasket diagnosis...
More common it seems is a head is cracked.
I wonder upon what basis the gasket diagnosis was made?
Anyhow, an engine sipping coolant does not have to be anything more sinister than a bad coolant cap.
The car does not have enough miles really to suspect the plugs, though if they are original they may be due to be replaced on time rather than mileage. Also, the misfiring is too spread out to likely be from a head gasket problem.
However, when replacing the plugs the tech can probably confirm one way or the other the head gasket theory, from the appearance of the plugs. A cylinder with coolant will produce a rather clean plug.
Absent clear signs there is a head gasket leak, with the history of the car, its lack of use, I'd be more likely to suspect mice damage to the wiring, hoses, maybe even a coolant hose. I've seen a hole chewed into a gasoline vapor line -- the creature probably stopped when it got a snoot full of gas vapor -- so there's no reason to believe the same couldn't happen to a coolant hose.
Before you decide what to do you need to know exactly what is wrong. Then you can make a better decision.
Let's say the head gasket is bad. You need to price a fix. Now you have to be careful. A long term coolant leak can compromise the head (or block) surfaces and a new gasket might not hold. The "fix" is to take a skim cut across the block and head to restore these surfaces to the flatness/surface finish that a head gasket requires to do its job. The skim cut may not be doable as the damage to the head or block is too severe. If the block needs doing the comes out of the car -- it may have to come out anyhow to get at the head -- and would need to be disassembled so the block could be machined, cleaned up, then put back together again. You want to be sure you have the right shop tackle this job. You can spend a lot of money having the block and head machined if they do not need it. But you can spend a lot of money doing the head gasket repair again on top of then having the block or head machined to ensure this time the head gasket holds.
You'll have to work the numbers to see what the damage is if you decide to fix the car vs. unload the car. As it sits with a suspected (and "diagnosed") head gasket problem, combined with misfiring, and what have you the car is not worth much. Thus you take a bit hit in depreciation. Of course you also know what you have lost. You are done with the car and can move on.
I wonder upon what basis the gasket diagnosis was made?
Anyhow, an engine sipping coolant does not have to be anything more sinister than a bad coolant cap.
The car does not have enough miles really to suspect the plugs, though if they are original they may be due to be replaced on time rather than mileage. Also, the misfiring is too spread out to likely be from a head gasket problem.
However, when replacing the plugs the tech can probably confirm one way or the other the head gasket theory, from the appearance of the plugs. A cylinder with coolant will produce a rather clean plug.
Absent clear signs there is a head gasket leak, with the history of the car, its lack of use, I'd be more likely to suspect mice damage to the wiring, hoses, maybe even a coolant hose. I've seen a hole chewed into a gasoline vapor line -- the creature probably stopped when it got a snoot full of gas vapor -- so there's no reason to believe the same couldn't happen to a coolant hose.
Before you decide what to do you need to know exactly what is wrong. Then you can make a better decision.
Let's say the head gasket is bad. You need to price a fix. Now you have to be careful. A long term coolant leak can compromise the head (or block) surfaces and a new gasket might not hold. The "fix" is to take a skim cut across the block and head to restore these surfaces to the flatness/surface finish that a head gasket requires to do its job. The skim cut may not be doable as the damage to the head or block is too severe. If the block needs doing the comes out of the car -- it may have to come out anyhow to get at the head -- and would need to be disassembled so the block could be machined, cleaned up, then put back together again. You want to be sure you have the right shop tackle this job. You can spend a lot of money having the block and head machined if they do not need it. But you can spend a lot of money doing the head gasket repair again on top of then having the block or head machined to ensure this time the head gasket holds.
You'll have to work the numbers to see what the damage is if you decide to fix the car vs. unload the car. As it sits with a suspected (and "diagnosed") head gasket problem, combined with misfiring, and what have you the car is not worth much. Thus you take a bit hit in depreciation. Of course you also know what you have lost. You are done with the car and can move on.